catch JS exceptions when using InvokeAsync and throw them in .NET

[campersau]

catch JS exceptions when using InvokeAsync and throw them in .NET

Exceptions in createJSCallResult and stringifyArgs were only thrown in JS before and .NET never received them.

Examples of exceptions which are now reaching .NET:

• aspnetcore/src/JSInterop/Microsoft.JSInterop.JS/src/src/Microsoft.JSInterop.ts

  Line 591 in 371bf37

  throw new Error(`Invalid JS call result type '${resultType}'.`);

• aspnetcore/src/JSInterop/Microsoft.JSInterop.JS/src/src/Microsoft.JSInterop.ts

  Lines 167 to 188 in 371bf37

  	if (streamReference instanceof Blob) {
  	length = streamReference.size;
  	} else if (streamReference.buffer instanceof ArrayBuffer) {
  	if (streamReference.byteLength === undefined) {
  	throw new Error(`Cannot create a JSStreamReference from the value '${streamReference}' as it doesn't have a byteLength.`);
  	}
  	length = streamReference.byteLength;
  	} else {
  	throw new Error("Supplied value is not a typed array or blob.");
  	}
  	const result: any = {
  	[jsStreamReferenceLengthKey]: length
  	};
  	try {
  	const jsObjectReference = createJSObjectReference(streamReference);
  	result[jsObjectIdKey] = jsObjectReference[jsObjectIdKey];
  	} catch (error) {
  	throw new Error(`Cannot create a JSStreamReference from the value '${streamReference}'.`);
  	}

• aspnetcore/src/JSInterop/Microsoft.JSInterop.JS/src/src/Microsoft.JSInterop.ts

  Line 148 in 371bf37

  throw new Error(`Cannot create a JSObjectReference from the value '${jsObject}'.`);

Fixes #40272 (references the last exception from the list above)
Fixes #41934 (exception in stringifyArgs)

[campersau]

Unrelated bonus test.

[mkArtakMSFT]

Thanks for your PR, @campersau.
@MackinnonBuck can you please review this? Thanks!

[campersau]

Updated to also catch exceptions during stringifyArgs which is the case in #41934 and added tests for synchronus Invoke to show that the behavior is the same as InvokeAsync, both throwing exceptions.

[MackinnonBuck]

LGTM

[MackinnonBuck]

Thanks @campersau!

[ghost]

Hi @MackinnonBuck. It looks like you just commented on a closed PR. The team will most probably miss it. If you'd like to bring something important up to their attention, consider filing a new issue and add enough details to build context.

[datvm]

Hi is this PR actually online yet? I am using .NET 7 Blazor WebAssembly (7.0.202) and I still have this issue. The code runs fine if JS returns something but does not returns when JS returns undefined (Error printed in Console but nothing happens on .NET side).

    public static async Task<T> GetGlobalObject<T>(this IJSRuntime js, string key) =>
        await js.InvokeAsync<T>(
            GetFullFuncName("getGlobalObj"),
            key);

    public static async Task<IJsWindowReference?> GetOpenerAsync(this IJSRuntime js)
    {
        var opener = await js.GetGlobalObject<IJSObjectReference?>("opener");
        return opener?.AsWindow(js);
    }

    getGlobalObj(key) {
        return globalThis[key];
    }

[ghost]

Hi @datvm. It looks like you just commented on a closed PR. The team will most probably miss it. If you'd like to bring something important up to their attention, consider filing a new issue and add enough details to build context.